Ground-engaging jacks are suspended from a vehicle and they are operated to lower the jack so that it contacts the ground to lift, support, or level the vehicle. Such ground-engaging jacks are used to level and/or support parked trailers, for example but not limited to, travel trailers or motorhomes broadly known as RV's. They are also used to lift and lower vehicles during maintenance procedures. When used with RV's, ground-engaging jacks are typically a permanent part of the vehicle, and they can be automatically or manually extended from a retracted stored position located beneath the vehicle to a working position for leveling or supporting the vehicle. When in the stored position, leveling jacks are typically positioned to extend beneath, parallel to the vehicle, and with the stored base member stored perpendicular to the ground. In some mounting configurations, the base will extend below the body of the vehicle. Since the clearance between the RV and the ground is limited, the base of the leveling jack often digs into high spots or obstructions at a campsite. In certain instances, the base and/or jack assembly will collide with high spots along a road surface when the RV is towed or driven from place to place. For example, the jack assembly may come into contact with speed bumps, smash into the road surface when the RV encounters abrupt road transitions, hits a pothole or road debris. Such unexpected road hazards can damage the jack assembly and may cause the jack to become inoperable. Furthermore, environmental road conditions such as rain, snow, and/or ice along with road salt, mud, dirt, or grime, will cause the stored ground-engaging jack mechanism to corrode and/or become coated with grunge making the jack difficult to operate or even making it inoperable. It should also be noted that when ground-engaging jacks are permanently fixed to a vehicle they create an aerodynamic drag on a moving vehicle. Such drag is eliminated when a ground-engaging jack is only fixed to the vehicle when in use to lift, support, or level the vehicle.
In the instance where a ground-engaging jack is used to raise or lower a vehicle during maintenance, it is extremely important to provide a secure and stable connection between the jack and vehicle to prevent accidental collapses and injury. Such collapses can be caused by placing the jack (or lift) in or at a position where the load rest does not make proper contact with the vehicle frame or it does not engage the vehicle at a correct location along the frame. Improper contact and/or engagement between a jack and vehicle is often the result of the jack base engaging ground surface irregularities such as depressions, humps, slopes, or the like, that cause the jack to extend at an unstable angle. The frame bracket of the present invention ensures that the load rest can only be attached to the vehicle at a predetermined position along the vehicle frame, and the combination standing bracket and sliding bracket provided by the present load rest enables the jack to engage the ground at a perpendicular lift angle between the jack and vehicle, and in particular, where the jack base engages an uneven or sloped ground surface.